Mounting of grenade launcher on firearm with stabilizer



1, 1951 J. c. GARAND 2,564,684

MOUNTING OF GRENADE LAUNCHER ON FIREARMS WITH STABILIZERS 2 Sheets-Sheet 1 Filed April 10, 1946 awe/Wm Jul-L11 l1 Elm-rand Aug 21, 1951 J. c. GARAND 2,564,684

MOUNTING OF GRENADE LAUNCHER 0N FIREARMS WITH STABILIZERS 2 Sheets-Shet 2 Filed April 10, 1946 d W n w M u .N 3 T mm i u ww G -i fi M n l.. N D s Q @N s J hm rm h N n QQ w W QM R- .m HH Q Q mwfimv 1| \\\\\\\T N g mm QM n WNNM MN Q ww \Q mv &

Patented Aug. 21, 1951 UNITED STATES TENT OFFHCE MOUNTI NG OF GRENADE LAUNCHER ON FIREARM WITH STABILIZER (Granted under the act of March 3, 1883, as amended'April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The present invention relates to improvements in mounting a grenade launcher on a firearm and more particularly on a firearm of the gas operated type.

As is well known, a grenade launcher is customarily attached to the muzzle of the firearm and the grenade is discharged from the launching device by firing a blank cartridge in such firearm. Modern infantry requirements demand that such accessories as grenade launchers be mounted without any modifications or changes in the basic weapon. Grenade launchers for gas-operated firearms are customarily associated with an escapement valve particularly adapted to reduce the high pressure of the actuating gases on the reeoiling members of the firearm when a grenade is launched therefrom. This has been accomplished in the art but it has been found necessary that other accessories such as recoil checks or stabilizers, which are also attached to the muzzle of the firearm, be incorporated as essential features of an infantry weapon. Obviously, therefore, it is desirable that provision be made to mount a grenade launcher on such rifles which embody a stabilizer without the necessity for first removing such stabilizer. It is also desirable that the type of mounting used be universal in nature so that other accessories, as a fiash hider for example, can be mounted on firearms provided with stabilizers.

Another essential feature of a grenade launcher mounted on a firearm requires that no removal or manual adjustment of the launcher be necessary in order to fire ball cartridges semi-automatically. In; other words. the user of a firearm adapted for grenade launching should be able to fire ball ammunition immediately should the occasion arise and by doing so will not affect the grenade launching device of the firearm.

Accordingly, it is a purpose of this invention to provide superior means for mounting a grenade launcher on a firearm equipped with a stabilizer or recoil check.

It is also a purpose of this invention that the means for mounting a grenade launcher on a firearm equipped with a stabilizer or recoil check be of such universal nature that other accessories, such as a flash hider, can be substituted for the grenade launcher quickly and conveniently. g Another purpose of this invention is to pro- 2 I vide a combination of grenade launcher, gre-, nade launcher valve and stabilizer for a firearm wherein the firearm can be used for launching grenades or firing ball ammunition at the will of the operator without the necessity for removal or adjustment of the grenade launcher.

It is a particular. purpose of this invention to provide a stabilizer and grenade launcher for attachment to the U. S. rifle, caliber .30, M1, particularly one adapted for full automatic fire.

Another particular purpose of this invention is to provide a fast acting latching means for the removal of firearm accessories, such as a grenade launcher, when the firearm is to be fired full automatic The specific nature of the invention as well as other objects and advantages thereof. will clearly appear from 'a description of apreferred embodiment as shown in the accompanying drawings in which:

Fig. 1 is an assembly view showing a grenade launcher mounted on a stabilizer carried on the muzzle of a firearm and showing the valve necessary for the operation of the grenade launcher.

Fig. 2 is a cross-sectional view taken along the line 2-2 in Fig. 1.

Fig. 3 is a rear end view of the grenade launcher.

Fig. 4 is a longitudinal sectional view of the assembly of Fig. 1.

Fig. 5 is a cross-sectional view taken along the line 5-5 of Fig. 1.

Fig. 6 is a cross-sectional View of the stabilizer taken along line 6-6 of Fig. 1.

Fig. 7 is a fragmentary longitudinal and sectional top view taken along line I'l of Fig. 1.

There is shown in Fig. 1 a grenade launching device designated by the numeral I, a stabilizer 2, and a grenade launcher valve assembly 3 assembled to the muzzle end of a gas operated firearm of the type known as the U. S. rifle, caliber .30, M1. A gas cylinder 4 is shown mounted beneath and locked to the end of a firearm barrel 5 in much the customary manner. In the construction of this invention, however, the usual gas cylinder lock 6 is incorporated as part of the stabilizer 2 and as in the firearm referred to above, the lock is threadably secured to the end of the barrel 5 but is here maintained in position by a grenade launcher valve assembly 3 inserted through the lower opening 1 of the gas cylinder lock and threaded into the forward end of gas cylinder 4.

A gas port 8 is provided in barrel 5 which communicates with a ort 9 in gas cylinder 4 thereby providing a passage as shown in Fig. 4 for the actuating gases to be admitted into gas cylinder 4 where such gases impinge on the face of a cooperating piston I therewithin. Piston I0 connects with the reciprocating parts of the firearm (not shown)..

In order to dissipate the actuating gases which are evolved when a grenade is launched, a valve assembly 3 is provided. As shown particularly well in Fig. 4, such valve assembly 3 consists of a housing I I provided with an axial hole or bore l2, the left end of which is conically counterbored to form a valve seat l3. Bore i2 is counterbored at the right end to accommodate a helical spring 24.

The housing terminates in a threaded end portion l5 which cooperates with threads in the forward end of gas cylinder 4. l lousing is also provided with a plurality of spaced holes I6 and slots H which break through into the axial bore I2 and act as gas ports.

A valve is contained within the valve housing II and comprises a forward spindle-like or stem portion l9 and a rear cone-shaped head portion I The underside of valve head 26 is shaped to conform to the conical valve seat l3 provided in axial bore l2. A collar 2| is securedto the front end of valve stem l9 by a transverse pin 22 and such collar 2| retains the helical spring 24 surrounding valve stem l9 within housing |.l.

As shown in'Fig. 1, the stabilizer 2 consists of a substantially semi-cylindrical body portion 25 having an integral and horizontally disposed tubular section 26 extending forwardly therefrom. Two oppositely disposed locking lugs 21 are provided on tubular section 23, the purpose 'of which will later be described. Extending from the rear of the stabilizer body portion 25 is an integral and horizontally disposed tubular se c,

tion 28 of a diameter corresponding to that of 1.,

the front tubular section 26 and oppositely disposed thereto. The rear tubular section 23 terminates in the integral gas cylinder lock 5 previously mentioned. The two tubular sections 26 and28 communicate with body portion 25 and are each provided with a longitudinal bore 29 said bores being in alignment with one another.

The body portion 25 of stabilizer 2 has two oppositely disposed and vertically. milled cuts 34.

A passage 30 extends transversely throu h the body portion 25 so as to' lie between bores 29 and in conjunction with the cuts 34 forms a centerpiece or bridge 3 I. An angular cut 32 is provided on the bottom of the left hand side of bridge 3| looking toward the rear of the firearm as shown in Fig. 6 'for a purpose to be explained later. A longitudinal bore 33 extends through bridge 3| and'c'ontains a latching device therein. The diameter of the forward portion 0f bore 33 is slightly larger than that of the rear portion thereof, thus forming a shoulder 35 against which a spring 35 is seated as described below;

The latch mentioned above consists of aplungor 31 having a head portion 38 ending in a truncated cone 39. Spring 36 surrounds plunger 31 and is confined within longitudinal bore 33 by head portion 38. plunger 31 in the longitudinal bore 33 and also secures a latch lever 4| adjacent the semi-circular body portion 25. lhe pin 43 is slightly bent after insertion, as shown in Fig. 2, to prevent accidental removal from the plunger 31. The latch lever 4| consists of a fiat portion 42 provided with an elongated hole 5| in the center. thereof to accommodate the plunger 31, the

A transverse pin 40 secures 4 bottom of portion 42 being shaped to conform to the outside periphery of the rear tubular body section 28 and an upper portion 43 extending substantially at right angles to the flat portion 42. The upper portion 43 of latch lever 4| is arcuately formed and serves as ,a finger piece.

As shown in Fig. 4, grenade launcher consists of an inner tube 44 inserted into an outer tube 45 of larger outside diameter and secured therein by a press-fit or can be made integral therewith. The outer tube 45 is provided with a plurality of annular ribs 46 on the outer periphery thereof which are used to position the grenade (not shown) according to the range desired. In this. invention, the rear end of the outer tube 45 is provided with an integral circular flange 41. The rear face of such flange .41 has .a groove 48 disposed somewhat off-center as shown in Fig. 3. Two oppositely disposed clearance cuts 49 are provided about the inner peripheryoftube .45 to allow insertion of the innertube ,44 into stabilizer 2., Such clearance cuts 49 form locking lugs 59 therebetween which mate with the stabilizer locking lugs 21 as will later be described.

In order to mount the grenade launcher on the stabilizer 2, the launcher inner tube 44 is inserted into the front tubular section 25 of the stabilizer 2. Launcher is then rotated either to the left or right so that the locking lugs 21 on the front tubular section 26 of the stabilizer 2 align With the clearance cuts 49 on the rear face of the launcher flange 41. The launcher I can then be forced further to the rear, until flange v41 Strikes e run at d coni al end 39 of the stag bilizer plunger head 38. Additional pressure e rwa d a ins aunch r I al o moves p un e er head 38 to the rear against the bias of spring 36. Then by rotating the launcher I once more either to the leftor right, the truncated conical end 39 of, plunger 31 urged by plunger spring 36 snaps into groove 48 and thereby prevents further rotation of launcher -Thus launcher is locked to stabilizer 2 by the stabilizerlocking lugs 21 engaging the rear surface of launcher locking lugs 50 as shown in Figs. 5 and 7.

To remove launcher I from stabilizer 2, the latch finger piece 43 is first depressed thereby withdrawing the truncated conical end 39 of plunger 31 from groove 48. Thereupon the procedure described above is substantially followed in reverse. V

When the grenade launcher is mounted on the stabilizer 2 and a grenade is launched, a

r substantial gas pressure is built up in barrel 5 and in gas cylinder 4. 1 The recoil initiated thereby causes launcher to overcome the bias of the plunger spring 36 and move up against the semicircular body portion 25 of stabilizer 2. The circular flange 41 of launcher thereby strikes the collar 2| and effects rearward displacement of valve stem I9 against the bias of valve spring 24. 7 Valve head 20 is thereby forcibly moved rearwardly and such displacement provides an avenue of escape for the actuating gases from gas cyl-. inder' 4 to the atmosphere through bore l2 and exhaust ports l6 and [1 in valve housing A portion of these gases, however, do impinge on the face'of piston H] but the pressure. of such residual gas is of low intensity and thereby imparts little, if any, recoil movement to piston l0 and-hence to the recoiling parts of the firearm, Otherwise, excessive recoil would frequently re-. sult in the breakage of the recoiling members.

W en t o l has. d ss a ed, he gr nade launcher l is urged forwardly by spring biased plunger 31 until lugs 21 contact lugs 50 thereby allowing valve assembly 3 to close under the urging of the valve spring 24. The conically shaped valve head 20 mates with the conical valve seat l3 thereby effectively sealing the valve housing H against the escape of any of the actuating gases. Thus the firearm can function normally to fire ball ammunition semi-automatically without the removal or adjustment of the grenade launcher, or if desired, another grenade may be launched. In this connectionit is pointed out that no ball ammunition should be fired when a grenade is mounted on the launcher as, obviously, disastrous results would occur.

When grenade launcher l is not mounted to stabilizer 2, a portion of the powder gases which are generated upon automatic firing of the weapon are free to flow into the atmosphere from the end of barrel 5 into tubular section 28 of stabilizer 2 and out through passage 30. As is well known, the continuous recoil of a firearm in automatic fire causes the muzzle thereof to climb upwardly. At the same time, there also exists a tendency for the muzzle to move to the right due to the spin imparted to the bullet by the right hand twist of the barrel rifling. Stabilizer 2 is therefore constructed so as to counteract both the aforesaid movements of the muzzle and thereby keep the firearm sights aligned with the target selected by the operator. As the discharge gases flow into the atmosphere through passage 30, they strike the front wall of body portion 25 and are thereby deflected rearwardly. As a result, the firearm is forced forwardly thereby substantially neutralizing the rearward recoil which, if continued, as in automatic fire, would cause the upward climb of the muzzle previously referred to. A portion of the discharge gases also strike angular cut 32 and are thereby deflected downwardly and to the right with sufficient force to neutralize the tendency of the firearm muzzle to move as the result of the spin of the bullet passing therethrough.

When the grenade launcher l is mounted on the stabilizer 2, the launcher inner tube 44 extends beyond the transverse passage 30 in the stabilizer body portion 25 and thereby prevents the action of the stabilizing features mentioned above. However, automatic fire with ball ammunition is seldom found necessary when the user of the firearm is prepared to launch grenades. Therefore the combination of a grenade launcher, stabilizer and grenade launcher valve is eminently suitable for all the essential purposes required thereof.

It can be also readily observed that if other accessories, such as a flash hider for example, have mounting means corresponding to that of the grenade launcher herein described, such accessories can be mounted in lieu of grenade launchers on a firearm provided with the stabilizer and latching device of this invention.

I claim:

1. In combination with a gas'operated firearm having a barre] and a stabilizer secured to the muzzle end thereof, a grenade launcher slidably mounted to the stabilizer for longitudinal reciprocal movement, means on said launcher for rendering the stabilizer inoperative, cooperating means on the stabilizer and on said launcherfor limiting the forward movement of the latter, and resilient plunger means carried in the stabilizer and arranged to engage with said launcher for preventing rotation thereof relative to the stabi- 6. lizer whereby said launcher is releasably latched to the stabilizer.

2. In combination with a gas operated firearm having a barrel and a stabilizer secured to the muzzle end thereof, a grenade launcher slidably mounted to the stabilizer for recoil and counterrecoil movement in longitudinal alignment with the barrel, means on said launcher for rendering the stabilizer inoperative, a plurality of outwardly projecting lugs radially disposed about the forward end of the stabilizer, a plurality of inwardly projecting lugs similarly disposed within said launcher and arranged to pass between said stabilizer lugs during assembly of said launcher to the stabilizer, and resilient plunger means slidably carried in the stabilizer for engaging with said launcher upon rotation thereof relative to the stabilizer whereupon said launcher lugs engage behind said stabilizer lugs under the bias of said resilient plunger means to releasably latch said launcher to the stabilizer.

3. In combination with a gas operated firearm having a barrel, a stabilizer fixedly secured to the muzzle end of the barrel and having a forwardly projecting tubular portion, a plurality of outwardly projecting lugs radially disposed about the forward end of said stabilizer tubular portion, a grenade launcher having a bore therethrough, means on said launcher for rendering said stabilizer inoperative, a plurality of inward- 1y projecting lugs radially disposed within said launcher bore, said launcher lugs arranged to slidably engage said stabilizer tubular portion and pass between said stabilizer lugs during assembly of said launcher to said stabilizer, resilient plunger means slidably carried in said stabilizer and arranged to engage with said launcher upon rotation thereof relative to said stabilizer whereby further rotation of said launcher is prevented,

said launcher lugs being thereby disposed behind said stabilizer lugs to limit forward movement of said launcher relative to said stabilizer, and means for retracting said plunger means out of engagement with said launcher for permitting disassembly thereof from the firearm.

4. In combination with a gas operated firearm having a barrel, a stabilizer fixedly secured to the muzzle end of the barrel, a forwardly projecting tubular portion on said stabilizer in axial alignment with the barrel, a plurality of outwardly projecting lugs radially disposed about the forward end of said tubular portion, a grenade launcher having a circular flange portion thereon, a tubular portion on said launcher extending rearwardly beyond said flange portion and arranged to be slidably disposed in bearing relationship within said stabilizer tubular portion for rendering said stabilizer inoperative, a plurality of inwardly projecting lugs radially disposed between said flange portion and said launcher tubular portion, said inwardly projecting lugs arranged to pass between said stabilizer lugs dur-- ing assembly of said launcher to said stabilizer, a plunger slidably mounted in said stabilizer for longitudinal reciprocating movement, resilient means surrounding said plunger and arranged to bias the latter forwardly, said launcher flange portion having a chordal groove on the rear face thereof for engaging the front end of said plunger to limit rotation of said launcher relative to said stabilizer, said launcher lugs being thereby disposed behind said stabilizer lugs for limiting forward movement of said launcher relative to said stabilizer, and lever means operative on the rear end of said plunger for retracting the front end thereof out of engagement with said chordal groove whereby said launcher is freev to rotate for disassembly from said stabilizer, all adapted. and arranged whereby the engagement of said plunger with said launcher is continuously maintained during the reciprocating: movement thereof effected by the launching" of a grenade.v

JOHN C. GARAND.

REFERENCES CITED file of this patent:

UNITED STATES PATENTS Number Number Name Date Cory Dec. 3, 1901 Van Voorhis Feb. 28, 1911 Gurney et a1 June 4, 1935 Smith Jan. 11, 1944 Reisi ng Aug. 22, 1944 Coates et a1 Feb. 25, 1947 Cutts Nov. 9, 1948 Garand Dec. 7, 1948 FOREIGN PATENTS Country Date France 1 Feb. 5, 1920 

